Zophopetes quaternata Mabille, 1876

Cock, Matthew J. W., Congdon, Colin E. & Collins, Steve C., 2014, Observations on the biology of Afrotropical Hesperiidae (Lepidoptera). Part 6. Hesperiinae incertae sedis: palm feeders, Zootaxa 3831 (1), pp. 1-61 : 20-23

Zophopetes quaternata Mabille, 1876

Mabille (1876) described Pamphila quaternata , which closely resembles Z. dysmephila (above), from Senegal. Evans (1937) treated Z. quaternata as a valid species, but suggested it might be a subspecies of Z. dysmephila , and subsequently he did make it a subspecies ( Evans 1947). Lindsey & Miller (1965), Gillies (1982), Ackery et al. (1995) followed Evans in this regard, for example Gillies considered that of 16 specimens in his collection from Gambia, 14 resembled quaternata and two dysmephila . However, Larsen (2005) recognized them as two separate species with consistent differences in the male genitalia, and this is the situation today. Adult Z. quaternata are readily recognised by the underside having a dense irroration of tiny blackish flecks, often with a slight reddish tone (the red tone not being evident in Figure 15 ) (T.B. Larsen pers. comm. 2013). Zophopetes quaternata is now known from Gambia and Senegal, east to Ghana ( Larsen 2005), with additional records from Nigeria ( Figure 15 ) and Cameroon, and a cluster in DR Congo (Virunga), south-west Uganda and north-west Tanzania (T.B. Larsen pers. comm. 2012). Records of Z. dysmephila from West Africa are misidentifications of Z. quaternata ( Larsen 2005) , as Z. dysmephila is at most found as far west as southern Cameroon.

Adult behaviour. We have no observations, but in Gambia, Gillies (1982) reported Z. quaternata ‘flying at great speed round Phoenix palms at dusk’.

Food plants. The record of Z. dysmephila from Phoenix reclinata at Lamto ( Vuattoux 1999) is referable to Z. quaternata ( Larsen 2005) . SCC has reared Z. quaternata from P. reclinata in Gambia (reported below), and MJWC has reared what appears to be Z. quaternata from P. dactylifera at Ibadan, Nigeria (94/107, 94/109).

Life history, Gambia. As the type locality for Z. quaternata is Senegal, the following observations from Gambia by SCC must represent the true Z. quaternata . In October 2010, SCC searched for skipper early stages on palms in the vicinity of Banjul, Gambia, where the naturally growing P. reclinata palms are under threat as the old swampy areas are being drained. He found two caterpillars of Z. quaternata on P. reclinata in a forest remnant amongst the deepest undergrowth, and reared one through.

The caterpillar ( Figure 16.1–2 ) is similar to those of the Z. dysmephila group, but the head has markings which are different, although more material is needed to assess variation. SCC’s photographs and the cast skin in ABRI show the head to be light brown, with dark brown-black markings on the posterior part of the head extending to the posterior margin, the epicranial suture, a heavy black line each side of the epicranial suture, which meet just above the adfrontals, and then run down the epicranium adjacent to the adfrontals to level with the clypeus, and the whole of the frons, but not the adfrontals. The pupa ( Figure 16.3 ) resembles those of the Z. dysmephila group.

Life history, Nigeria. MJWC reared this species at Ibadan, Nigeria, where they were causing significant damage to small Phoenix palms planted as ornamentals in Mar 1994 (94/107, 94/109).

Caterpillars of 6 and 8mm (instar n-3): head 1.2 x 1.4mm wide x high (n=2); light brown; epicranial suture dark; dark black pronotum; body translucent green. A 13mm caterpillar (instar n-2) was similar: head 2.0 x 2.2mm wide x high; broadly and diffusely dark in a band from vertex to stemmata; epicranial suture and upper part of clypeal suture dark; slightly separated from epicranial suture, and adjacent to adfrontal sutures very diffuse, slightly darker band from below vertex to level with mid frons, with inner margin more sharply defined.

Five penultimate instar caterpillars of 22–28mm were collected, and a description was prepared of one of 23mm. Head nearly oval, but widest below centre, slightly indent at vertex, 2.4 x 2.9mm wide x high (n=6); semiprognathous; ground colour light brown with dark brown markings: dorsal half of posterior margin, a detached diffuse line from bottom end to stemmata, stemmata, epicranial suture, upper part of adfrontals, a heavy stripe each side of epicranial suture, a diffuse mark on epicranium adjacent to adfrontals level with the top of frons, which is also dark; mouthparts brown. Narrow black pronotum. Body dull yellow-green; dorsal line dull green; pale subdorsal line (within ground colour) T2–A8; anal plate with brown tint; spiracles brown; legs concolorous. The intensity and extent of the markings on the face varied between individuals ( Figure 17 ). A narrow black line across the front of the anal plate ( Figure 17.2 ) in one individual was thought to be an artefact where a piece of the moulted skin of the previous instar with the pronotum had stuck to the body of the moulted caterpillar.

The final instar caterpillar was not described or photographed at the time, and the following is based on four caterpillars preserved in ethanol. Head 3.3 x 4.2mm wide x high (n=4); rugose; ground colour light brown, as penultimate instar; diffuse dark brown band from vertex to stemmata, the upper third against posterior margin, the lower part swinging forwards to the stemmata, the intensity varying between individuals; epicranial suture dark, but not strongly so; upper part of adfrontal and clypeal sutures dark in some individuals; black line from below vertex, close to epicranial suture to level with top of adfrontals, a black spot on the epicranium adjacent to adfrontal, at level of mid frons, more or less in line with the black line (similar to Figure 17.1 but more strongly marked). In another individual the black line continues to join the spot against the adfrontal, while two were intermediate with the black line partially or almost separated from the black spot; two individuals had a dark line down the centre of the frons. Narrow black pronotum, divided at the dorsal line.

The pupa ( Figure 18 ) is similar to those of the Z. dysmephila group: 24mm; smooth in outline with no projections; head and thorax light chestnut brown; appendages and abdomen light brown; spiracle T1 dark brown. Groups of scattered brown, forward-directed setae on thorax and eyes. The inside of the shelter and the pupa lightly dusted with white waxy powder.

Discussion. The caterpillar of Z. quaternata from Nigeria is of the same general form as that of Z. quaternata from Gambia, and in common with that population, the posterior part of the head is dark. However, the markings on the face, especially the black frons of the Gambia population differ from the reduced markings found in Nigeria. The possibility that Z. quaternata occurs in geographically separated subspecies should be considered. Furthermore, the caterpillars of Z. quaternata from Nigeria ( Figure 17 ) seem closer to those of Nairobi typical Z. dysmephila ( Figure 7 ) than to Gambian Z. quaternata ( Figure 16 ). Given the variation in caterpillars and male genitalia discovered in Z. dysmephila above, it seems clear that further investigation should be directed at both species.

Figures

FIGURE 7. Final instar caterpillars of Zophopetes dysmephila, collected on Phoenix reclinata, Nairobi, Kenya. 1, dorsal view; collected as caterpillar, 13 May 1989; moulted to final instar 15 May; photographed 18 May 1989; 26mm; 89/37. 2, detail of head, anterodorsal view; collected as caterpillar, 24 Jun 1989; photographed 24 Jun; pupated 7 Jul; 89/49. 3, detail of head, anterodorsal view; as #1.

FIGURE 15. Adults of Z. quaternata reared from pupae collected 19 Mar 1994 on Phoenix sp.?dactylifera, Ibadan, Nigeria; 94/107. 1, male, emerged 23 Mar; 94/107B; 2, female emerged 22 Mar; 94/107A. The fine dark irroration on the underside, characteristic for this species, can be seen.

FIGURE 16. Final instar caterpillar and pupa of Zophopetes quaternata, collected on Phoenix reclinata, Oct 2010, Banjul, Gambia [SCC]. 1, head, anterodorsal view; 2, final instar caterpillar dorsal view; 3, pupa, dorsal view.

FIGURE 17. Penultimate instar caterpillars of Zophopetes quaternata, collected 19 Mar 1994 on Phoenix sp.?dactylifera, Ibadan, Nigeria; 94/109. 1, detail of head, anterodorsal view; 2, caterpillar, dorsolateral view, same individual as #1; 3, detail of head, reduced markings, anterodorsal view; 4, caterpillar, dorsolateral view.

FIGURE 18. Pupa of Zophopetes quaternata, lateral view, collected 18 Mar 1994 on Phoenix sp.?dactylifera, Ibadan, Nigeria; 24mm; 94/107.